Smokeless powders, low explosives that serve as propellant in ammunition, are typically analyzed in the unburned or burned forms. Forensic laboratories utilize chemical profiles for confirmation of powder type or association of evidence at a crime scene to a potential suspect. Recent research utilized targeted liquid chromatography (LC)-mass spectrometry (MS) to distinguish powders according to ammunition brand. This work demonstrated use of a non-targeted approach for compound identification combined with multivariate statistical analysis for association and discrimination of powders. Smokeless powders, both unburned and burned, were analyzed from commercial ammunition of different caliber, manufacturer, primer composition, and age. Preliminary morphological analysis was limited. Chemical analysis was performed using LC-atmospheric pressure chemical ionization-time-of-flight MS with multiplexed collision-induced dissociation for non-targeted compound identification (LC-APCI-multiplexed CID-TOF-MS). Increasing collision energies fragmented ions to different extents, providing structural information and facilitating compound identification, even without suitable reference standards. Principal components analysis of the chemical profiles generated distinct groupings of powders based on the presence of ethyl centralite, 1-methyl-3,3-diphenylurea, diphenylamine (DPA), N-nitroso-DPA, and dibutyl phthalate. Hierarchical cluster analysis produced a complementary analysis with the same groupings. Association of burned powders to unburned counterparts was possible, although the extent of association was dependent on the unburned powder composition and the extent of compound depletion during firing.
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